1. Technical Field
This invention generally relates to a roadway warning system, and more specifically relates to such a system that includes a transmitter for transmitting a signal regarding the status of a visual traffic directing device.
2. Background Art
Various systems and devices are used to direct traffic and to regulate the flow of traffic through intersections. Such systems typically use visual indicators such as lights and/or signs to communicate instructions to drivers of vehicles approaching intersections. For example, a typical traffic light includes a green light that tells a driver to proceed through the intersection, a yellow light that tells a driver that the light is about to turn red, and a red light that tells a driver to stop before reaching the intersection.
Present visual indicators generally work well. However, their reliance on the human visual sense is problematic because vehicle drivers are often inattentive, distracted, or are otherwise unaware of the message communicated by the visual indicators. Many intersection accidents result from the ineffectiveness of the reliance on the visual sense. Currently in the United States, operators are involved in approximately 1.8 million intersection accidents per year causing over 500,000 injuries of which approximately 7,000 involve fatalities.
Several different warning systems have existed that warn drivers of the status of visual traffic directing devices, such as traffic lights. Examples of such systems include U.S. Pat. No. 5,594,432 to Oliva et al., issued Jan. 14, 1997; U.S. Pat. No. 5,748,006 to Hochstein, issued Jul. 21, 1998; U.S. Pat. No. 5,635,920 to Pogue et al., issued Jun. 3, 1997; and U.S. Pat. No. 5,633,629 to Hochstein, issued May 27, 1997, each of which is incorporated herein by reference. Such systems have typically been complicated in operation and have not been sufficiently effective in warning drivers of upcoming traffic lights or other visual traffic directing devices.